icholson, at Glasgow, in 1807, he had been steadily improving in
this art, the knowledge of which is indispensable to whoever aspires to
eminence as a mechanical engineer,--until by general consent Clement
was confessed to stand unrivalled as a draughtsman. Some of the very
best drawings contained in the Transactions of the Society of Arts,
from the year 1817 downwards,--especially those requiring the
delineation of any unusually elaborate piece of machinery,--proceeded
from the hand of Clement. In some of these, he reached a degree of
truth in mechanical perspective which has never been surpassed.[2] To
facilitate his labours, he invented an extremely ingenious instrument,
by means of which ellipses of all proportions, as well as circles and
right lines, might be geometrically drawn on paper or on copper. He
took his idea of this instrument from the trammel used by carpenters
for drawing imperfect ellipses; and when he had succeeded in avoiding
the crossing of the points, he proceeded to invent the straight-line
motion. For this invention the Society of Arts awarded him their gold
medal in 1818. Some years later, he submitted to the same Society his
invention of a stand for drawings of large size. He had experienced
considerable difficulty in making such drawings, and with his
accustomed readiness to overcome obstacles, he forthwith set to work
and brought out his new drawing-table.

As with many other original-minded mechanics, invention became a habit
with him, and by study and labour he rarely failed in attaining the
object which he had bent his mind upon accomplishing. Indeed, nothing
pleased him better than to have what he called "a tough job;" as it
stimulated his inventive faculty, in the exercise of which he took the
highest pleasure. Hence mechanical schemers of all kinds were
accustomed to resort to Clement for help when they had found an idea
which they desired to embody in a machine. If there was any value in
their idea, none could be more ready than he to recognise its merit,
and to work it into shape; but if worthless, he spoke out his mind at
once, dissuading the projector from wasting upon it further labour or
expense.

One of the important branches of practical mechanics to which Clement
continued through life to devote himself, was the improvement of
self-acting tools, more especially of the slide-lathe. He introduced
various improvements in its construction and arrangement, until in his